So had to change a drive out on a AHU with 2 fans. Got all done, programmed up, and checked operation. Both return and exhaust fans are over amping. Both direct drive and original. Open return and looped duct sock on supply. Have no blower specs, so I just measure velocity from openings. Stop the unit and look at the fans. They look like backwards incline fans, because of the fatter section of the blades normally goes into the air. So I reverse the command to the drives. Velocity jumps way up and amp draw goes down.
So now I'm thinking....why does amp draw go up when these were running backwards. Less air....less work....less amperage, no?
I never really ran one backwards and checked flow and amperage.